The main objectives of this proposal are to produce Copenhagen line 2331 x Fischer 334, F1 hybrid male rats bearing R3327, a prostatic adenocarcinoma. The inoculated animals will be provided to investigators in the National Prostatic Cancer Project and extra material will be retained as a resource of frozen R3327 for in vitro studies. The plan is to maintain our production of F1 hybrids to obtain 75 male rats/week. The rats will be inoculated with R3327 and used in research projects relating to human prostatic cancer. Experiments will be conducted in an attempt to increase the incidence of metastases of R3327 in addition to supplying tumor-bearing rats.